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ASN Wikibase Occurrence # 212526
Last updated: 12 August 2019
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Time:17:05 LT
Type:Silhouette image of generic E55P model; specific model in this crash may look slightly different
Embraer EMB-505 Phenom 300
Owner/operator:Satu Aviation
Registration: HB-VYS
C/n / msn: 50500181
Fatalities:Fatalities: 0 / Occupants: 2
Other fatalities:0
Aircraft damage: None
Category:Serious incident
Location:Grenchen Airport (LSZG) -   Switzerland
Phase: Approach
Departure airport:Belfast City Airport (BHD/EGAC)
Destination airport:Grenchen Airport (ZHI/LSZG)
Investigating agency: STSB Switzerland
After an uneventful flight from Wangen-Lachen (LSPV), the pilot of the Robin DR400, registered as HB-KLE, listened out the airport and weather information (Automatic Terminal Information System - ATIS) from Grenchen (LSZG), after which runway 06 was issued as the runway in operation. After the pilot's first call to the air traffic control centre, the air traffic controller reported at 17:00:38 that the control zone and thus the class D airspace were no longer active and that all users should continue with blind calls. Thus the Radio Mandatory Zone (RMZ) was active.
A few seconds later, the crew of the Embraer Phenom 300 business jet, registered as HB-VYS, reported at 17:00:54 hours for the first time on the frequency of the Grenchen air traffic control centre for a direct approach to runway 24 as follows: "HBVYS Grenchen Echo VFR descending to the final track for runway 24". After a flight rule change from IFR to VFR had been carried out over the Jura at about 16:58 hrs, HB-VYS subsequently approached Grenchen Airport from the east according to visual flight rules. Half a minute later the crew of the HB-VYS reported at Wangen at an altitude of 4800 ft QNH and a ground speed (GS) of 240 kt with the words: "Grenchen HBVYS approaching Solothurn VFR".
Since the Landing Distance Available (LDA) of runway 06 is 135 metres shorter, the operating company preferred runway 24 up to a tailwind component of 8 knots for a landing for operational reasons. According to the HB-VYS pilot, this is known both to the air traffic control centre and to the local flight operating companies; normally, an approach to runway 24 would be smoothly coordinated by the air traffic controller upon request.
According to the air traffic controller, the change of flight rules and the estimated time of arrival (ETA) had been coordinated with the approach control centre in Bern Arrival; the ETA of HB-VYS fell within the period of the active Radio Mandatory Zone (RMZ). After the crew had reported to Solothurn for the second time, the traffic control centre again pointed out that blind calls had to be made. At that time, Grenchen airfield had a low crosswind with respect to the runway direction at a wind speed of 4 knots.
At 17:01:59 a pilot of another small airplane, registered as F-PIMS, reported himself in descent from the west for a landing on runway 06. Approximately one minute later the pilot of HB-KLE reported himself above the reporting point Whiskey in 2400 ft QNH for a landing on runway 06. At 17:03:34 the crew of HB-VYS reported themselves in the final approach of runway 24. At this time their GS amounted to 235 kt.
The HB-KLE was in the right base approach to runway 06 at that time when the pilot heard this position report concerning HB-VYS. Then at 17:03:42 he sent the following radio message: "H-LE turning long final runway 06 for landing". About half a minute later, the pilot of the F-PIMS reported at 17:04:25 h above the reporting point Whiskey for landing on runway 06.
As the crew of the HB-VYS announced later, the renewed indication of the air traffic control centre regarding blind calls in the final approach required an intensive airspace surveillance in order to get a picture of the other aircraft. About one mile before the runway threshold 24 the GS was 170 kt. Since the final approach was not stabilised, the crew initiated a go around without reporting this on the frequency.
Uncertain whether an aircraft actually approached runway 24 or whether it was a misunderstanding, the pilot of the HB-KLE continued his approach. Shortly afterwards a passenger in the HB-KLE drew the pilot's attention to the landing lights of the business jet approaching on the opposite runway. Subsequently, they watched as the HB-VYS made a take-off over the runway threshold. At about the same time the pilot of the HB-KLE was made aware of the business aircraft taking off by the aerodrome traffic manager, whereupon the pilot HB-KLE took a left turn. During the climb, the HB-VYS exceeded the HB-KLE by about 500 ft. The horizontal distance at the time of the closest approach was about 0.1 NM.

STSB conclusions:
This dangerous approximation shows, by way of example, that the number of reported incidents concerning dangerous approximations between aircraft in aerodrome traffic around Grenchen airport has massively increased since the introduction of the Radio Mandatory Zone (RMZ).
The present concept as well as the accompanying publications harbour comprehensive risks, especially when changing the type of operation, which is why there is an urgent need for a thorough revision.
After a period of two years, the FOCA temporarily terminated the pilot project "IFR without air traffic control service" at the end of March 2019. IFR approaches were not scheduled until the end of May. In addition, the recalculated IFR departures will be validated over the summer of 2019. The permanent RMZ with IFR traffic in the airspace of the Golf class is planned for Grenchen Airport (LSZG) from March 2020, provided that the validation has been successful.

Weather about the time of the incident (17:05 LT / 1505Z):
LSZG 011420Z VRB03KT 9999 FEW032 SCT045 13/04 Q1013 NOSIG
LSZG 011520Z AUTO VRB03KT CAVOK 14/04 Q1013


Accident investigation:
Investigating agency: STSB Switzerland
Status: Investigation completed
Duration: 1 year and 3 months
Download report: Final report


Flight tracks of HB-KLE and HB-VYS; G = airspeed in KIAS graphic: STSB

Revision history:

22-Jun-2018 20:09 harro Added
12-Aug-2019 15:03 harro Updated [Nature, Destination airport, Narrative, Accident report, ]
12-Aug-2019 16:18 harro Updated [Photo]

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